Like long-known roller blind systems, such covering has the disadvantage that the removal of articles from certain parts of the cupboard unit--for example from those which are located in the region which faces away from that edge of the covering which borders the opening--inevitably involves complete opening of the covering. However, this is often undesirable since, for example, it takes more time than, for example, opening a cupboard door which is fastened to hinges and indeed also makes all areas of the cupboard accessible. This is the case regardless of whether the roller blind is operated by hand or by an electric motor, as described in German Offenlegungsschrift 3,531,675.
For lining surfaces, coverings in the form of wall carpets for example Gobelin tapestries, as well as curtains are also known and can be raised or lowered by means of tapes guided by pulleys.
Such coverings have been disclosed, for example, for cupboard units or their front coverings and are distinguished by their small space requirement during opening and by a stylish shape. German Offenlegungsschrift 3,531,675 describes such a cupboard unit.
The known designs of front coverings for boxes, for example according to the stated German Offenlegungsschrift, permit the covering to be left partly open, with the effect of displaying articles behind the covering in the cupboard unit for a longer time. However, in the areas described above, which face away from that edge of the covering which borders the opening, this is possible only by complete opening of the coverings. Consequently, the other areas cannot be hidden or concealed.
The same also applies to curtain or roller blinds, all of which allow a partial opening to be left only below their lower edge (or only to the side of the lateral edge). If it is desired, for example, to allow sunlight to enter a room through a window opening, this is possible only with simultaneous visual exposure of the lower part of the window.
Divided roller blinds have also been disclosed (for example in German Patents 211,972, 221,575 and 549,678). These roller blinds permit partial display, for example for the middle area--i.e. the section between those two edges of the two roller blind parts which border the opening--of the cupboard unit which they close. However, for the sections which are remote from the stated edges, the disadvantage mentioned above is applicable. Moreover, these roller blinds are however connected to one another by means of ropes or chains in such a way that they can only be moved in conjunction with one another. Opening the upper roller blind in an upward direction automatically results in opening of the lower roller blind in a downward direction; the objects of the invention therefore cannot be fully achieved by such a known design.
On the other hand, connection of the upper and lower roller blinds is necessary since, in the known designs, it is necessary to prevent automatic opening or closing of the roller blinds through their own weights.
Divided cupboard units are also known, in which in principle a cupboard unit with an upward-opening roller blind is provided at the top and a cupboard unit with a downward-opening roller blind is provided at the bottom--the two roller blinds being separate from one another. It is true that such embodiments are somewhat better with regard to the independence of opening, since the upper roller blinds can be moved independently of the lower roller blinds; in the end, however, they merely constitute a doubling of a cupboard unit according to German Offenlegungsschrift 3,531,675 (one of them positioned upside down), which requires a greater amount of material but nevertheless only partly achieves the objects of the invention.